Coupled & Ocean Modelling @ MPI-M

Johann Jungclaus

Max-Planck-Institut für Meteorologie

Ocean model development at MPI-M has presently two foci:

Maintain and improve the Max Planck Institute Ocean Model (MPIOM) as part of the MPI-M Earth System Model (E. Maier-Reimer, H.Haak, J. Jungclaus, J-S. v. Storch)

Develop a new ocean model in co-operation with new atmosphere model ICON (P. Korn, S. Lorenz, PhD students)

Momentum, Energy, H2O, CO2

LandHD

JSBACH

AtmosphereECHAM5/6

Solar variations

Volcanic aerosolCO2 emissions

Natural forcingAnthropogenic forcing

Land use change

CH4, N2O, CFC conc.

OceanMPIOM

HAMOCC

The MPI-M Earth System Model

• ECHam5/6 (Roeckner et al., 2003), interactive runoff and glacier calving scheme.

• Land surface JSBACH (Raddatz et al., 2007), Dynamic Vegetation (Brovkin et al., 2009)

• New Radiation• Resolution: T31L19, T63L47, T127/L95, …..

• OASIS 3.0 coupler

• MPIOM

The MPI-M Earth System Model

• MPIOM (Marsland et al., 2003), • C-Grid, z-level, partial cells, BBL parameterization• Isopycnal diffusion, GM (Gent et al., 1995; Griffies et al., 1998)• Vertical mixing: PP and mixed layer wind mixing• Hibler-type sea ice model incl. snow and fractional ice cover• Conformal mapping grid: dipole or tripole• Ocean biogeochemistry module HAMOCC5 (Wetzel et al., 2007)

MPIOM

dipole global application:

GR3.0 and GR1.5

dipole regional application

MPIOM- grid set-upsdipole grid

Tri-polar, quasi-homogeneous

1°, 0.4°, 0.1°

tripole grid set-up

Paleo applications

PETM (55 Ma)

PhD thesis M. Heinemann

dipole grid

Miocene (15 Ma)

PhD thesis M. Krapp

tripole grid

Resolution mattersGriffies et al., 2009

MPIOM: TP04

Griffies et al., 2009

MPIOM: TP04

Resolution matters (sometimes…)

Applications

• long (and, or many) integrations with effective low-resolution ESM (T31/GR3)

• Ensemble simulations of the Last Millennium

• Multi-millennia transient experiments (e.g. Holocene)

• Sensitivity experiments in paleo environment (e.g., PETM, Miocene)

Example: Last Millennium

• first ensemble simulations over the last 1200 years using comprehensive ESM including interactive carbon cycle. (In total, almost 20000 years of data!)

HadCRUT2vCRUTEM2vExpt. 1 Expt. 2

Expt. 4 Expt. 2

Expt. 3

anomalies w.r.t. 1961-1991 mean

•Simulation captures warming trend over 19th/20th century

•Observed multidecadal variations partly due to internal variability

Northern Hemisphere temperatures:the instrumental period

Northern Hemisphere temperatures:the last 1200 years

solid: 5 full forcing expts. (Krivova solar 0.1%)

dashed: 3 full forcing expts. (Bard solar 0.25%)

• Range of variability consistent with observations, but LIA cooling less pronounced than in reconstruction for 0.1%

Background shading: overlay of reconstructions (after IPCC, 2007)

Simulation of CO2 evolution

Solid lines: full forcing ensemble E1 (Krivova solar, 0.1%)

dashed lines: full forcing ensemble E2 (Bard solar, 0.25%)

Grey shading: Overlap of reconstructions (C. Reick)

Applications

• Decadal prediction and ocean initialization • No data assimilation for MPIOM available, but

benefit from Detlef Stammer‘s GECCO work in the neighborhood

• Presently testing several „assimilation“ techniques in AR4 set-up (ECHAM5 T63L31 MPIOM GR1.5L40) : SST (Keenlyside et al., 2008),

• GECCO (Pohlmann et al., 2009)• Forced (NCEP) MPIOM runs (Matei et al., in

prep.)

SAT hind minus 20C COR skill for lead time 1yr

NCEP GECCO

Gain in skill

SAT hind minus 20C COR skill for yr6-10

NCEP GECCO

Gain in skill

STORM-project (J.S. v. Storch)

- using IPCC AR5 model system (ECHAM6/MPIOM-TP)

- long climate change simulations (i.e., 20 century run + 21 century run with RCP4.5 forcing)

- horizontal resolution in the ocean: ~ 1/10 degree (10km)

- horizontal resolution in the atmosphere: ~ 50 km

Scientific foci (among others):

- Climate sensitive & dependence of climate sensitive on resolution (e.g. whether and to what extent will climate projections change due to enhanced resolution)

- Impact studies (e.g. changes of extreme value statistics…)

MPIOM at high resolution (0.1°)

a snapshot of horizontal velocity speed at 57 m [m/s]

• MPI-M will run CMIP5 experiments 20th century, projections, and decadal forecast using ECHAM6 T127/L95 MPIOM 0.4/L80 „HR“

• Paleo and historic (last millennium) will be run at T63L47 (ECHAM6) and 1°L40 (MPIOM) „LR“

• Expts with interactive chemistry will be run at „LR“ at FZ Jülich (M. Schultz)

ECHAM6/MPIOM in CMIP5

CO2 CONCENTRATION 2423

control 1850 C 500

1850-2005 C+2*T1 3*156

RCP4.5 2006-2100 C+2*T1 3*95

RCP4.5 2101-2300 T1 200

RCP8.5 2006-2100 C+2 3*95

RCP8.5 2101-2300 T2 200

RCP2.6 2006-2100 T1+2 3*95

RCP2.6 2101-2300 T2 200

CMIP5 ECHAM6/MPIOM-HR

C: CORE, T1: Tier1, T2: Tier 2

CO2 Emission 1003

Control C-cycle C 250

1850-2005 C-cycle C 156

RCP8.5 2006-2100 C-c. C 95

1850-2005 decoupled T1 156

RCP8.5 2006-2100 dec. T1 95

1850-2005 rad. only T2 156

RCP8.5 2006-2100 rad. T2 95

CMIP5 ECHAM6/MPIOM-HR

C: CORE, T1: Tier1, T2: Tier 2

Initialized decadal 2700

Initialized, 10 yr 30*C+70*T1 100*10

Initialized, 30 yr 6*C+14*T1 20*30

Initialized - volcanoe 15*T1+35 50*10

Initialized + volcanoe 3*T1+7 10*10

CMIP5 ECHAM6/MPIOM-HR

C: CORE, T1: Tier1, T2: Tier 2

Paleo: PMIP3 6000

control mid holocene 2000

control LGM 2000

Control Millennium 2000

1400

Mid holocene T1 100

LGM T1 100

Last Millennium T2 1200

Total 7400

CMIP5 ECHAM6/MPIOM-LR

C: CORE, T1: Tier1, T2: Tier 2

Working fields

• Tides (E. Maier-Reimer, M. Müller)

• New sea ice model (D. Notz)

• Vertical mixing (E. Exarchou, J. v. Storch, JHJ)

• Adaptation for high resolution (0.1° or higher) models (non-hydrostatic, non-boussinesq (E. Maier-Reimer))

Tides

• Ephemeridic module of Thomas et al. [2001] implemented in MPIOM

• Analytical ephemerides for the sun and moon calculated with sufficient accuracy for tidal applications (~0.1‘ for the sun, 1-2‘ for the moon) [van Flandern and Plukkinen, 1998]

• Real-time forcing of complete lunisolar tidal potential

New sea-ice model

• A representation of the frazil-pancake cycle and the associated brine release

• An improved representation of salt fluxes from ice during growth and decay

• Multi-layer, multi-category sea-ice thermodynamics

• Improved albedo scheme (Pedersen et al., 2009)

• Dynamics on triangular grid for ICON is planned

The new sea-ice model will include:

• Coupled atmosphere & ocean model on identical grid type• Icosahedral grid: unstructured grid that avoids problems of

lat/lon grids: pole singularity, non-uniformity of grid cells• Collaboration with German Weather Service (DWD)• Includes data assimilation• Joint pool of physics packages • From short & local to long & global time-space scales weather

and climate prediction

• Local model refinement: horizontal & vertical

• regional/local modelling

• covering hydrostatic & nonhydrostatic regime

ICON: MPI-M's Next Generation Climate Model

ICON Development Branches

2D shallow water

3D hydrostatic atmos. dynamical core

ICOHAM as successor of

ECHAM

3D non-hydrostatic numerics

3D hydrostatic ocean

+ ECHAM physics

The ICON Grid

Concept of patches for refinement for domain decompositionUnstructured grid minimize distance between neighbors in memory only relationships between neighbors are stored: no traditional array data structure

Ocean model versus Atmosphere model

one external modea few fast vertical modes, vertical mode decomposition every time step

Elliptic problem for...

operators: divergence, vorticity, gradientelliptic solver, time stepping

Commons

Equations

z levelshybrid terrain followingVertical coordinate

Hydrostatic OceanHydrostatic AtmosphereModel

Primitive equation model with a free surface Discretization of vector-invariant form of momentum equation

Spatial Discretization: C-type staggering Normal velocity: at triangle edges Temperature & salinity: at triangle centers Free surface elevation: at triangle centers

Temporal Discretization: semi-implicit two-timelevel scheme

ICON Ocean model

Dynamics

1st version of dynamical core implemented and tested

Physics (work-in-progress)

Forcing Momentum/heat/fresh-water fluxes (CORE-project)Bulk formulas

ParametrizationsVertical mixing, convection Grid-dependent physics (GM) requires substantial development

ICON Ocean model

Ocean data assimilation/state estimation using adjoint method

Adjoint model via adjoint compiler adjoint compiler as integral part of ICON-Ocean model automatic generation of adjoint code

Strategy ICON-Ocean development parallel with adjoint development collaboration with Prof. U. Naumann (RWTH Aachen)

Current status adjoint ICON-shallow-water model available

ICON Ocean model: further development